Selective calling apparatus.



E. B. CRAFT L G. BROWN.

SELECTIVE CALLING APPARATUS.

APPLICATION FILED IIIIIE 30` 1910.

Patent-d May 18, 1915.

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" by @@W E. B. CRAFT L e. BROWN.

SELECTIVE CALLING APPARATUS.

APPLICATION FILED JUNE 30,1910. JZ. Patented May18, 1915.

2 SHEETS-SHEET 2.

by MAW UTED STATES ATENT .EDVJ'ARD IB. CRAFT, 0F HACKENSACK, NEW JERSEY,AND GREGORY BROWN, 0:1 BROKLYN, NEW YORK, ASSIGNORS TO WESTERN ELECTR-CCMPANY, F MEW" YORK, Il'. Y., A CRPOEAATIQN OF ILLINOIS.

SELECTIVE CALING- APFARATUS.

Specification of Letters Patent.

'TQ all 'whom it may concern:

lie it known that we, EDWARD B. CRAFT and GREGORY BRowN, citizens of theUnited States, residing, respectively, at Hackensack, in the county ofBergen and State ot' New Jersey, and at Brooklyn, in the county of Kingsand State of New York, have invented a certain new and useful`lmprove'ment in Selective Calling Apparatus, of which the following isin full, clear, concise, and exact description.

rThis invention relates to selective calling apparatus i'or telephoneexchange systems and more particularly to a selector device designed foruse on a party line and adapted, in response to impulses sent out from acalling station, to complete a signaling circuit over which the party attheway station receives certain notifications, such as signals toanswer, time signals, etc. The invention is directed more particularlyto a selector having two magnets, one being a slow-acting onecontrolling a pawl adapted to engage a ratchet wheel to hold it againstrotation in one direction, the other being a quick-acting one andadapted, in response to' impulses sent over the line, to step saidratchet wheel around to a definite position determined by apparatus atthe calling station.

inthe class o'f telephone work to which this selector is particularlyadapted, there will be a number oi stations on a single line, eachstation provided with a selector responsive to impulses sent out from acalling station. the several selectors being adapted to close asignaling contact, in response to a different number oi' impulses fromthe sending station; that is to say, while all of the selectors respondto the impulses sent out over the line when one station is being called,the number. of impulses which will close the circuit i'or signaling theparty at any one station on the line will not complete the signalingcircuit at any other station on the line. lt is 'frequently desirable,however, in this class ol work to send a certain class of signals to allstations simultaneously, and one of the objects of this invention is toprovide means lor closing a second or auxiliary circuit for thereceiving of time or like signals al the way stations. Preferably this.circuit is completed through a contact on the selector frame which isengaged by the contact carried by the ratchet wheel-these contacts, butclosed on all contacts in the case of each selector being closed by a,dii'erent number of impulses than are required to close the 'callingsignal selectors by the same number oi impulses.

Another feature of this invention includes 1s a view in front elevationwith parts` broken away; Fig. 3 is a vertical sectional View taken uponline 3-3 of Fig. 2; Fig. 4 is a horizontal sectional view taken uponline 4% of Fig. 2; Fig. 5 is a. bottom view of the selector.

in the drawings, l designates a base member upon which is mounted an iiverted U- shaped frame preferably vformed oi' sheet metal having sidemembers 2, 2, a top niember 3 and supporting lugs 4, 4. Mounted withinsaid U-shaped frame are two electromagnets 5 and 6, each comprising twocoils, the coils of each magnet being secured together at their upperends by a yoke 7 of magnetic material secured tothe cores of the coils.The magnets are mounted in the frame by suspending them from the topmember 3 of the U-shaped frame, each of said magnets being secured bymeans oli' two machine screws 9, 9 passing through a raised portion 10on said frame and engaging serew-threaded apertures in the yoke 7. Aslotted set screw l2 passing through said raised portion l0 bears uponthe yoke 7 midway between the ends thereof. The use oi' the holdingscrews 9, S) engaging the yoke 7 permits of easy adjustment oi' themagnets for increasing or decreasing the air gap and the set screw l2will hold them firmly in their adjusted position. The raised portion l0uponY the top plate oi' the frame is for strengthening said top plate atthe points where the screws are supported. Pivotally supported near thelower end of the U- shaped frame are armatures la and 15, the

Patentes nay is, reis.

'tion 22 upon the lower tace of the adjacent armature while av secondset screw 23 inserted through the inturned portion of said member 2() isadapted to engage the upper face of said armature. With this arrangementbothv the extent and the position of the angle through which thearmature'moves can be governed to a certain' extent, it be` ing evidentthat as the set screw 21 is moved inwardly or outwardly, the positionwithrespect .to a h'orizontal plane which the armature ,will assume whenin its lower position may be varied vwithin certain limits; likewise byvarying the position of the set screw-23 the extent oli the movement ofsaid Aarmature may be varied.A rThis "feature permitsof amore accurateadjustment of the operating parts of the selector las will hereinafterappear.

As hereinbefore mentioned one of the magnets is a slow-acting oneadapted to hold a ratchet wheel against rotation in. one direction-theother being arranged to step said ratchet wheel around to apredetermined position. As shown, the armatures 14 and 15 are providedwith arms 25 and'26, respectively, which are brought out throughopenings in the trame and extended vertically upward. Attached to theupwardly extending arm Q5 is an arm '27 carrying at its upper end apivotally mounted pawl Q8 adapted in the movement ot said armature toengage the teeth ot a ratchet wheel 29 supported upon the frame in themanner hereinafter described. A spring 31 secured at one end to saidpawl and at its other end to the arrn Z7 tends to torce said pawl intoengagement with the ratchet wheel 29.` A laterally projecting finger 32on said pawl is adapted to be engaged by an arm 35 controlled by thearmature 15 to force said paw] 28 out of engagement with the teeth ofsaid ratchet wheel. Mounted upon the arm 26 of the armature 15 is ametal stamping 33 carrying arms 34, and 3G, the arm 35 being for thepurpose of pressing the pawl 28 out of engagement with the ratchet wheel29 as hereinbefore described, the arm 34 being for th'e purpose otdisengaging a holding pawl 40 from the ratchet wheel and the arm 36being for the attachment of a spring 41 which is adapted. when themagnet 6 is denergized. to return the armature 15 to its normalposition. As shown in Fig.

2 the holding pawl 40 is in the form of a bell crank lever-one arm beingadapted to engage the' teeth of the ratchet wheel 29, the othei" armthereof being adapted tor engagement by the upper end of the arm 34.

Secured to the frame of the selector on the side member thereof carryingthe ratchet wheel 29 are tension members 45 and 46, the tension member45 being located to the left of the ratchet wheel and having one arm tothe lower end of which is attached one end of a spring 47, the other endof which spring is attached to the armQ?, said spring being adapted toact through said arm to return the armature 1.4 to its normal positionwhen the magnet 5 is denergized. The member 46 is provided with two armsto which are attached springs 41 and 48,` the spring 41 being for thepurpose ot returning the armature 15 to normal position and the spring48 being secured at its other end to the pawl 40 for the purpose ofdrawing it into engagement with the ratchet wheel 29 when the magnet Gis energized. The tension oic the springs 41, 47 and 48 is adjusted bybending the respective arms to which their outer ends are attached.

As shownin the drawings, the ratchet wheel 29 is mounted in an auxiliaryframe 50 removably secured to the main iframe of the selector, saidratchet wheel being provided with a spindle 51 having conical .ends

engaged b v set screws 52 and extending through the walls of saidauxiliary frame 50. A helical spring surrounds the spindle 51 and isadapted to return said ratchet wheel to its normal position when bothmagnets are released. l

Referring now to the arrangement or" con tacts whereby the signalingcircuits hereinbefore referred to are completed, same is follows:Carried upon the ratchet wheel 29 is an arm 60 having an offset portion61 at its outer end upon which is mounted an 'outwardly facing Contactmember 62. Said contact member 62 is adapted in the rotation of saidratchet wheel to engage a con tact G3 carried by the upper end of aspring 64 mounted on one side of said ratchet wheel. The spring .64 ismounted upon a projecting support 67 formed' integrally with the maintrame. Said spring 64 is iiexible and is provided `at its upper end witha laterally projecting finger 65 which engages an insulating block uponthe outer face of the arm 27. The exibility of the spring 64 and itsconnection with the arm 27 causes it to partake of the movement of saidarm 27 as it operates to step around the ratchet wheel 29,' thusbringing it into contact with the Contact member 62 on the forwardmovement of the arm 27 or during the time that the stepping magnet 5 isen f conductor.

medico 63 will be engaged only during one the stepping magnet. Vlhen inits normal position the Contact arm rests against an insulated stop 70,carried by a depending; stop arm 7l which is itself insulated from theauxiliary frame 50. Mounted upon the opposite side of the arm 7l, fromthat against which the arm 60 rests when in normal position, is acontact 72 which is in position to be engaged by conpoint 62 when theratchet wheel is rotated through substantially a complete revolution. Aterminal strip 75 'connected with the depending arm 71 is brought outthrough an insulating bushing 76 ,in the frame 50 for connection with aconductor. A terminal strip '80 connected with the spring (il extendsdownwardly through a hole in the base l for connection with a Anotherconnection is completed through the selector frame. The stop arm 7l ismade adjustable so that by swinging it to the right or left, the numberof steps necessary to close the contacts 62 and SS may be increased ordecreased.

A projecting ear v85 formed integrally with the auxiliary frame 50 formsa support for a stop screwi which is adapted to limit 'the forwardmovement of the pawl ,28. lnasmuch as the arm 27 carrying the pawl Q8 isrigidly secured to the armature let these elements move together and thepositions ot the arm with respect to the ratchet r-.f'li 4' in which themovements of sai arm will take place may be varied by varying the extentand position of the angle through which said armature moves. By varyingthis movement the points on the p 'ph or' the ,ratchet wheel 29 at which.t8 will engage therewith may be mitting of a finer and more ment ot theoperating parts. on oit" a selector made as hereinheore described is asfollows: At the lirst' impulse' of current which. comes over the line,both magnets will be operated, but the 'adjustment 'oi' the parts issuch that this also will not step 'the ratchet Wheel 'forward but willbring the holding pawl into engageinei'it with said ratchet Wheel. Thesucceeding' impulses, however', will step the ratchet wheel around andthe holding pawl being controlled by the slow acting ma met will he heldin engagement with the ratchet wheel during the time that the impulsesare operating the stepping magnet; lllhen the contact 6:2 of theselector at the called station. has been broughtinto register with itscontact 63, the movement of the selector will bestopped for an intervalwith the contacts G2, '63, completinga circuit through signalingydevice. i This circuit will remain closed a certain interval undercontrol ot the sending' apparatus when the current will be cut off fromthe line, de-

the stations simultaneously, a suilioient number of impulses will besent out to step all of the selectors around until the contact pointsG2, 72 are brought into engagement. The same number orp impulses overthe line will step all of the selectors around until the contacts 62, 72are closed.

The use of the U-shaped iframeinclosing the electromagnets andproviding' a mount ing for the operating parts of the selector makes acompact piece of apparatus with all of the 'parts easily accessible.'lhe means of adjusting the tension of the springs by the `tensionmembers 45 and 45, thus doing' away with the screws or other likeadjusting mea-ns susceptible to jar and vibration, is also ofconsiderable advantage. rEhe selec tor when in use will he mounted uponsuitable base and the parte protected either by a porcelain or glass Weclaim:

l. ln a selector device the combination with a frame embracing top andside members, of magnet coils suspended from said top member, armaturespivotally supported between said side members below said coils, armsformed integrally with said armatures and eXtending outwardly andupwardly along the outer face oit one ot the side members, an auxiliaryframe removably mounted upon the side of theiirst mentioned frameadjacent to said arms, a ratchet wheel pivo "ly supported upon saidauxiliary iframe, spring pressed pawls operatcd by said for turning saidratchet wheel in one direction., and a helical spring operating to turnsaid ratchet wheel in the opposite direction.

2. ln a selector device, the combination with a trame, of a ratchetwheel mounted thereon, an oscillsfitiiu;` operating arm adapted. to bemoved to step said ratchet wheel around, an arm carried by said ratchetwheel, said arm having an offset portion at its outer end, a contactcarriedvby said offs 1 end, allen ible spring inoi'ented on said frame,a laterM all-y projectiirig` ringer on said spring, an insulating' knobon the baci; of said operating arm against which said linger normallybears, and a contact on said flexible spring adapted to be brought intoengagement with the contact carried on the ratchet wheel. arm duringzonestep only of said wheel.

3. In a. selector device, the combination hood.

with electromagnets and a fra-me therefor,

upon the magnet frame near the periphery iiis' oflsaid ratchet Wheel andwith which said movable contact arm registers when said ratchet wheelhas been moved through adeinite angle, a stop arm mounted on saidauxiliary frame` and insulated therefrom, an insulated stop on said armagainst which the movable contact arm rests when in normal position, anda contact on said stop arm adapted to be engaged by the contact on thearm carried by the ratchet wheel when said ratchet wheel has beenrotated the full extent of its movement.

5. 1n a selector device the combination with an inverted U-shaped frame,of an electromagnet suspended therein, an armature responsive .to saidelectromagnet pivotally supported in said frame below said magnet, saidarmature being provided with a beveled portion, a ratchet wheel mountedupon one side of said frame, operative connections between said ratchetwheel and saidl armature, a cross bar mounted upon said frame adjacentto said armature, an upwardly and incross bar, a conical ended set screwextending through the upwardly extending portions of saldl member and'engaging the beveled portion of said armature, and a set screwextending through saidA nturned portion of said member in position toengage the upper face of said armature.

In witness whereof, we hereunto subscribe our names this 29th day ofJune A. D., 1910. EDWVARD B. CRAFT.'

GREGORY BROWN.

Witnesses:

IRVING MACDONALD,

F. P. MoIN'rosH.

ywardly extending member carried by said

